In a conventional semiconductor manufacturing process, it is required to repeatedly conduct plural different processes such as, for example, a thermal processing, a film forming, and an etching in relation to semiconductor wafers (hereinafter, simply referred to as “wafers”). Since such various processes are often performed in different processing apparatuses, it may be required to convey wafers between the processing apparatuses. Accordingly, in order to prevent attachment of foreign matter to the surfaces of wafers or formation of a native oxide film on the surfaces of wafers when conveying the wafers, the wafers are accommodated in a substrate storage container (e.g., a wafer carrier) called FOUP (Front-Opening Unified Pod) and conveyed in a state where the cleanliness within the container is maintained at a predetermined level. The FOUP includes a container in which a plurality of wafers may be horizontally disposed and a cover installed on the front side of the container. The cover is provided with a lock apparatus and the FOUP is configured such that the wafers may be hermetically accommodated therein.
Meanwhile, each processing apparatus that conducts a processing for the wafers is formed with a wafer conveyance port through which the FOUP loaded with the wafers may be carried into the processing apparatus. The wafer conveyance port may be opened/closed by an opening/closing door according to the FIMS (Front-Opening Interface Mechanical Standard). The opening/closing door includes a cover removal apparatus configured to remove the cover installed on the front side of the FOUP, and is configured as a cover opening/closing apparatus. That is, the opening/closing door is required to perform various roles including opening/closing the cover so as to deliver wafers between the inside of the FOUP and a wafer conveyance area within the processing apparatus, and isolating the wafer conveyance area within the processing apparatus from the carrier conveyance area so as to maintain the wafer conveyance area at a low concentration of oxygen.
Specifically, when removing the cover, the cover removal apparatus acts on the lock apparatus installed on the cover so as to release locking in a state where the front side of the FOUP is closely contacted with the wafer conveyance port. Then, the cover removal apparatus is moved toward the wafer conveyance area side within the processing apparatus in a state where the cover removal apparatus retains the cover which is unlocked, thereby opening the wafers within the carrier to the wafer conveyance area. When opening the FOUP, nitrogen gas is purged between the opening/closing door and the FOUP so that the wafers carried out from the FOUP are not exposed to oxygen and the wafers are carried into the processing apparatus in a state where oxygen is prevented from being introduced into the processing apparatus.
Japanese Patent Laid-Open Publication No. 2010-56296, for example, discloses an opening/closing system includes a load port which is provided with nozzles configured to eject a gas to the surface of a cover so as to remove foreign matter.